Lean Control for Make‐to‐Order Companies: Integrating Customer Enquiry Management and Order Release

A lead time that is short, predictable, and reliable is an increasingly important criterion in supplier selection. Although many companies may achieve this through lean implementation, high‐variety manufacturers, for example, small and medium‐sized make‐to‐order companies, have found that lean's planning and control techniques do not apply. This article outlines a planning and control concept known as workload control (WLC) that integrates customer enquiry management, including a due‐date setting rule, with order release control. Simulation is then used to assess its impact on shop performance. Results demonstrate that an integrated WLC concept can reduce the percentage of tardy jobs—so short lead times can be realistically quoted—while also reducing and stabilizing workloads. WLC can level demand and production over time when work is not standardized and it is not possible to synchronize flows on the shop floor. Results are shown to be robust to changes in routing characteristics, the mix of orders with due dates specified by the customer and proposed internally, and the strike rate (or order‐winning probability). Hence, an integrated approach to WLC represents an important step toward achieving lean in make‐to‐order companies.     

A new skew-bimodal distribution with applications

The modeling and analysis of experiments is an important aspect of statistical work in a wide variety of scientific and technological fields. We introduce and study the odd log-logistic skew-normal model, which can be interpreted as a generalization of the skew-normal distribution. The new distribution can be used effectively in the analysis of experiments data since it accommodates unimodal, bimodal, symmetric, bimodal and right-skewed, and bimodal and left-skewed density function depending on the parameter values. We illustrate the importance of the new model by means of three real data sets in analysis of experiments.     

The Log-Normal zero-inflated cure regression model for labor time in an African obstetric population

In obstetrics and gynecology, knowledge about how women''s features are associated with childbirth is important. This leads to establishing guidelines and can help managers to describe the dynamics of pregnant women''s hospital stays. Then, time is a variable of great importance and can be described by survival models. An issue that should be considered in the modeling is the inclusion of women for whom the duration of labor cannot be observed due to fetal death, generating a proportion of times equal to zero. Additionally, another proportion of women''s time may be censored due to some intervention. The aim of this paper was to present the Log-Normal zero-inflated cure regression model and to evaluate likelihood-based parameter estimation by a simulation study. In general, the inference procedures showed a better performance for larger samples and low proportions of zero inflation and cure. To exemplify how this model can be an important tool for investigating the course of the childbirth process, we considered the Better Outcomes in Labor Difficulty project dataset and showed that parity and educational level are associated with the main outcomes. We acknowledge the World Health Organization for granting us permission to use the dataset.     

The expected impact of the 2019 Brazilian pension reform on survivors’ pensions

This study analyses the expected changes in survivors’ pensions resulting from the permanent rules of the 2019 pension reform in Brazil. Actuarial annuities are used for representative worker profiles. The dispersion in the replacement rate values decreases, except for the highest income level. The rates needed to finance survivors’ pensions decrease relatively more than do the rates for old-age pensions. The internal rates of return significantly decrease. There is a heterogeneous change in the distributive aspects of the pension system. The reform shall affect the adequacy and intragenerational equity of old-age and survivors’ pensions.     

What if your boss is a woman? Evidence on gender discrimination at the workplace

Review of Economics of the Household - In this paper, we exploit rich cross-country survey data covering 15 European countries over the period 2000–2015 to investigate the relationship...     

Impact measurement and dimension reduction of auxiliary variables in calibration estimator using the Shapley decomposition

Statistical Methods & Applications - In multipurpose surveys several interest variables and a very large number of auxiliary variables are collected. Auxiliary variables are usually considered...     

Job Tenure,Labour Mobility and Wage Profiles

Abstract. The features and the length of the attachment of workers to firms represent a central aspect of the labour relationship. The length of service is an important determinant of wages and of non-pecuniary benefits; it affects internal mobility in the firm, and insulates workers with long job tenure from unemployment. In this paper it is argued that the traditional “spot” labour market Characterization is difficult to reconcile with the existence of long term employment relationships. A number of alternative theories which predict the existence of an employer-worker attachment proposed, and their implications discussed. The relevance of long term employment relationships is then tested using micro-data for the Italian manufacturing industry. An appropriate methodology for the analysis of the duration of employment is developed. and separate “job tenure” equations for white and blue collar workers are estimated. A higher educational attainment - ceteris paribus- appears to increase the probability of a job separation; conversely, a higher working experience, previous to the current job, tends to reduce it. The effect of firm size is negative, as larger organizations seem to favour longer employment spells. Outside opportunities show a strong positive effect on the probability of separation. Finally, conditional on the current wage, the probability of leaving the job increases with the length of time worked. However, when the unconditional outcome is considered, separation decline with tenure; in this case. it is argued, the wage effect more than outweighs the conditional effect. This result is consistent with the predictions of both “specific” human capital and job matching theories.     

Influence of habitat type and distance from source area on bird taxonomic and functional diversity in a Neotropical megacity

The Neotropical region has been subjected to massive urbanization, which poses high risks for some global biodiversity hotspots and losses of ecosystem functions and services. In this study, we investigate how distance from large patches of native forests (source areas) and vegetation (green)/and infrastructure (gray) characteristics affect bird species richness and functional diversity in São Paulo megacity, southeastern Brazil. We analyzed the effects of source areas and green/gray characteristics on species richness and functional diversity (richness, evenness, and divergence) indices. We detected 231 bird species, and our data confirmed our predictions: (1) bird species richness in urbanized habitats was found to be (~?50–85%) lower than in source habitats; (2) species richness and trait composition significantly decreased as the distance from the source area increased, while functional richness was not affected by this metric; and (3) shrub and herbaceous covers and maximum height of trees were positively correlated with species richness and unique functional traits regarding habitat, diet, foraging and nesting strata and dispersal ability of birds in the forest-urban matrix. The number of buildings was negatively correlated with bird species richness and functional richness. Maximum height of buildings caused dramatic declines in functional evenness. Functional divergence was notably lower in sites with high shrub cover. Our study stresses the complexity of vegetation embedded in large Neotropical urban settlements and the need to maintain large protected areas surrounding megacities to mitigate the impacts of urbanization on birds.